Method for detecting performance degradation in radio base stations due to intermodulation products

Abstract

A method of detecting the degradation of a transceiver performance due to intermodulation products in radio base stations is disclosed. In an embodiment of the invention, the method includes measuring the received signal strength for each individual receiver frequency and recording the operational state of all transmitters. A plurality of data samples are used to determine a correlation between the received frequencies and associated disturbance. The degradation of signal reception caused by intermodulation (IM) products is derived from the correlated samples. If the performance is found to be below a predetermined value, a notification is initiated upon which corrective action can be taken. The method provides for prompt indication of poorly performing transceivers due to interference from IM products.

What is claimed is: 
     
       1. A method of detecting degradation of a transceiver performance in a base station due to intermodulation products created in said base station, wherein said base station comprises a plurality of transceivers each of which includes a transmitter and a receiver and each of which operate at a designated frequency, said method comprising the steps of: measuring, at said base station, a received signal strength for a first receiver frequency;   recording an operational state of said base station transmitters at the time of said received signal strength measurement;   correlating the recorded transmitter states with said received signal strength; and   determining an affect on transceiver performance due to said intermodulation products created in said base station from said correlating step.   
     
     
       2. A method according to claim 1 wherein said step of measuring received signal strength is performed for a second receiver frequency. 
     
     
       3. A method according to claim 2 wherein said step of recording the state of all transmitters is performed for each receive signal strength measurement on said second receiver frequency. 
     
     
       4. A method according to claim 1 wherein a plurality of samples are taken that are comprised of data for received signal strength and state of transmitters. 
     
     
       5. A method according to claim 4 wherein the quantity of samples taken is one thousand. 
     
     
       6. A method according to claim 1 wherein said determining step further includes the step of notifying a system operator when the performance level is determined to below a predetermined value. 
     
     
       7. A method according to claim 6 wherein said predetermined value in said determining step is a five on a scale of zero to ten. 
     
     
       8. The method of claim 1, further comprising the step of: inducing said intermodulation products in an antenna of said base station by operation of non-linear components disposed in said base station.   
     
     
       9. A method for monitoring operation of a base station comprising the steps of: generating intermodulation products within said base station, which intermodulation products are routed back to an antenna of said base station;   determining an effect of said intermodulation products on a receive frequency at said base station by performing the steps of:   measuring a received signal strength on said receive frequency;   identifying an operational state of a plurality of base station transmitting units; and   correlating said received signal strength with said operational states to determine said effect of said intermodulation products on said receive frequency.   
     
     
       10. The method of claim 9, further comprising the steps of: measuring a received signal strength on a plurality of receive frequencies; and   determining, for each receive frequency, whether that frequency is affected by a combination of operating base station transmitters.   
     
     
       11. The method of claim 9, further comprising the step of: reporting said effect to a mobile switching center.   
     
     
       12. The method of claim 9, further comprising the step of: notifying an operator if said effect exceeds a predetermined threshold.